Sky and Telescope - May 2017 - 58

MAY 2017 OBSERVING
Going Deep

Under a dark, transparent sky NGC
5529 looks great in scopes 6 inches
and larger, and if you're observing with
friends, you may be tempted to call
them over for a look. At magnitude 12.9
it's fainter than the better-known NGC
4565 - perhaps the most famous edgeon galaxy - and is less than half its
apparent length (6.2 arcminutes versus
15.9). But that only means you'll have
to look a little more closely to see the
details, which are more abundant than
those of NGC 4565.
The real treat of observing NGC
5529 is that it's presented almost

NGC 5529
SDSS J141555.31
+ 361333.9
PGC 50925
PGC 2076904
PGC 50952

NGC 5684

13.3

15.9

1.5′ × 1.3′

14h

NGC 5695

13.2

12.9

1.5′ × 1.1′

14h 37.4m

+36° 34′

14.4

16.8

0.9′ × 0.7′

14h

15.3m

+36° 12′

ﬁcult to say exactly where they stop. I
haven't been able to see the subtle warp
on the northwest tip of the galaxy yet,
perhaps because contrast decreases
rapidly toward each end.
The central dust lane also has low
contrast and is rather subtle despite
my large scope. I've seen it best with
averted vision, although it does suggest
itself with direct vision. The dark lane
extends some 50% of the full length
of the galaxy and is a bit off-center,
suggesting the galaxy is ever so slightly
tilted to our view.
The peanut-shaped central bulge of
NGC 5529 indicates it's a barred spiral,
similar to our Milky Way. Interestingly, we know the northwest end of the
galaxy is rotating toward us. The central
bulge is the brightest part of the galaxy,
but it barely extends beyond the disk. It
looks rather elongated and somewhat
boxy, with ﬂat sides. The southern half
is the brighter of the two and is a little
wider than the northern half, with
the dark lane being the most obvious
here. Both sides of the central bulge are
subtly brightest at the midline of their
borders with the dust lane.
The overall effect of all this is that
NGC 5529 looks long and slender,
which makes it an enormously appealing sight.

Kregel B

18.9

14h 15.6m

+36° 12′

The Companions

IKPM 1

19.8

0.2′ × 0.2′

14h 15.7m

+36° 13′

IKPM 2

17.0

0.5′ × 0.5′

14h 16.0m

+36° 17′

At last count, NGC 5529 had 16
companion galaxies, 12 of them with
NGC numbers. Together, they provide
as much, if not more, of an observing
challenge as our main target. Surprisingly, only one of the NGC compan-

exactly edge-on to us, long and slender.
It's huge, too: With an approximate
diameter of 250,000 light-years, it's
nearly twice the length of our Milky
Way galaxy.
The ends of the galaxy fade quickly,
and even in my 28-inch scope it's dif-

NGC 5529 Galaxy Group Members
Surface
Brightness

Mag(v)

Size/Sep

Dec.

NGC 5529

13.5

12.9

6.2′ × 0.8′

14h 15.6m

+36° 14′

NGC 5533

13.6

12.2

3.1′ × 1.9′

14h 16.1m

+36° 21′

27.1m

+36° 34′

Object

NGC 5544

12.9

13.6

1.1′ × 1.0′

14h

NGC 5545

12.6

14.0

1.5′ × 0.5′

14h 03.5m

+35° 01′

18.4m

+36° 30′

NGC 5557

12.6

11.7

2.3′ × 1.9′

14h

NGC 5589

13.3

13.6

1.1′ × 1.1′

14h 21.4m

+35° 16′

21.6 m

+35° 12′

NGC 5590

13.5

12.5

1.8′ × 1.8′

14h

NGC 5596

13.2

13.6

1.1′ × 0.8′

14h 22.5m

+37° 07′

NGC 5614

13.4

12.2

2.5′ × 2.2′

14h 24.1m

+34° 52′

NGC 5656

12.8

12.7

1.9′ × 1.5′

14h 30.4m

+35° 19′

NGC 5675

13.8

13.0

2.8′ × 1.0′

14h 39.7m

+36° 18′

35.8m

+36° 33′

PGC 50925

Angular sizes and separations are from recent catalogs. Visually, an object's size is often smaller than the
cataloged value and varies according to the aperture and magnification of the viewing instrument. Right
ascension and declination are for equinox 2000.0.

PGC 50950

M A Y 2 0 1 7 * SK Y & TELESCOPE

HOWA RD BA NICH

Thin and Beautiful

u Magnifications of 408× and 476×
were used to make this sketch. The
three bright stars in a line off the
southeastern end of the galaxy form a
distinctive part of NGC 5529's field of
view, and are the brightest part of the
scene, ranging in magnitude from 11.1
to 13.8. Out of the five companion galaxies shown, only PGC 50925 is physically associated with NGC 5529 and is
probably responsible for warping the
galaxy's northwestern end. The other
three galaxies observed by the author
are just outside this field of view.

Sky and Telescope - May 2017

Table of Contents for the Digital Edition of Sky and Telescope - May 2017